Acta Musei Moraviae

Molybdenite-pyrite ore mineralization in quartz veins and greisenized granite at Nová Bystřice near Jindřichův Hradec

Revision of mineralogical situation of ore mineralization in granites at Nová Bystřice near Jindřichův Hradec confirmed the presence of molybdenite-pyrite mineralization. The local pyrite mined in the 17th century was used as a source of sulfur for the producing of gunpowder, and also iron sulphate and sulfuric acid. Silver-bearing and gold mineralization was not found, the ore contains only 14.7 ppm Ag and <0.1 ppm Au. Pyrite disseminated ore occurs in greisens and muscovite- quartz-rich granites of the Central Moldanubian Pluton. Abundant quartz veins in pinkish feldspatized granites (K-metasomatites) contain molybdenite as major ore mineral. The oxidation zone is only slightly developed, along supergenne minerals goethite and jarosite(?) dominated, a unique mineral is ferrimolybdite and sporadically was found native sulfur.